Fluid-pressure engine



(No Model.)

' R. A, PARKE.

FLUID PRESSURE ENGINE.

No. 508,525. Patented Nov. 14, 1893.

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UNITED STATES PATENT ()FFICE.

ROBERT A. PARKE, OF NEW BRIGHTON, ASSIGN OR .OF ONE-HALF TO JOHN BOYDTEACHER, OF ALBANY, NEW YORK.

FLUID-PRESSURE ENGINE.

SPECIFICATION forming art of Late. Patent 1\T 0.508,525,dated November14, 1893. Application filed August 4:, I893- Serial No. 482,383. (Nomodel.)

To all whom it may concern: j

Be it known that I, ROBERTA. PARKE, a

citizen of the United States, residing at the village of New Brighton,county of Richmond,

5 and State of New York, have invented certain new and usefulImprovements in Fluid- Pressure Engines or Motors, of which the following is a specification.

' My invention relates to the economical use. to of steam, compressedair or other fluids, in the operation of engines or motors, under suchcircumstances that more or less frequent starting and stopping of thesame are essential to the purposes for which they are employed.

It is well known that the economical use of steam, compressed air orother gases requires that, after the admission of such gas to theoperating cylinder through a certain portion of the travel of thepiston, the admission of the gas under pressure must then be cut off andthe gas permitted to expand during afurther portion of the movement ofthe piston. It also frequently occurs that, when the engine has beenfairly started,it is, for the'sake of economy, desirable to permit thecompressed gas to enter the Working cylinder only during a shorterperiod of the travel of the piston than was necessary when the operationof the'engine' began. 'Forthis purpose, suit- 0 able arrangements of thevalve motion controlling the entrance of the compressed gas to theworking cylinder are used, so that, by the movement of alever or othersuitable connection with the valve gear, the operator may 5 permit theentrance of the necessary volume of gas in starting and subsequentlyreduce the volume entering to that which will give a greater economy inthe use of the same. It also frequently occurs that, in order to cause 0the engine or motor to quickly attain considerable speed, it isdesirable to admit the gas to the working cylinder of the motor at ahigher pressure than is subsequently desirable for the economicaloperation of theengine. In cases therefore wherefit is necessary toquickly start an engine or motor into operation while under a load, itis necessary that the operator should control both the degree ofpressure under which the gas enters the working cylinder and, also, thevolume of the same which shall enter the working cylinder. This requiresintelligence and thoughtfulness on the part of the operator,in as muchas negligence on his part to reduce the pressure of the gas enteringtheWorking cylinder, or to reduce the volume of gas admitted to the workingcylinder, or both, will result in an extravagant use of needless wasteof power. My invention is intended to prevent such waste of power, bycausing the pressure and volume of the gas to be automatically reducedto the economical amount predetermined after the engine or motor hasbeen fully started, and by requiring a physical exertion on the part ofthe operator against an elastic resistance, to increase either thepressure or volume of gas admitted to the working cylinder at the timeof starting.

Briefly stated, my invention consists in the combination of a valveoperating mechanism having a free predetermined movement such as willpermit the passage through the valve of a definite volume or pressure ofair, steam or gas, in combination with an elastic resistance device soarranged and connected with 7 the valve operating mechanism that anygreater movement of the valve will be opposed by the elastic resistance.

To enable others skilled in the art to make and use my invention, I willnow describe it by reference to the accompanying drawings, which form apart of this specification and in which Figure 1 represents the floorplan of a street car operated by a motor, wherein compressed air is usedas the motive power, the motorbeing so connected by levers and rods,that it may be operated from either end of the car and both the degreeof pressure and volume of air entering the working cylinder of the motorare established for the economical operation of the same, when the caris under headway. It also shows my improvements which permit the use ofa somewhat greater pressure or the entranceof a somewhat greater 5volume of air in the working cylinder, either separately or inconjunction, only by the operator overcoming the resistance of a springin either case. Fig. 2 is a detailed view, in section, of an arrangementof one of the reroo sisting springs. Fig. 3 shows a modification of theapparatus, by which my'invention may be utilized in connection with thereversing lever of a locomotive or other engine, operated in thatmanner.

The compressed air is stored in a reservoir or reservoirs mounted on thecar in the usual way, as will be well understood, and is conductedtherefrom through tube 1 to a reducing valve 2 which may be any suitableone of the several well known forms found in the market, and it istherefore unnecessary to give a detailed description of the same. Thespring of this reducing valve is adjusted so that only a certainpredetermined pressure, regardless of the pressure in the reservoir ortube 1, can enter the tube 3 which is connected with the opposite end ofthe valve. Projecting from the side of the reducing valve 2 is a stem 13which is held outward to a certain normal position by the regulatingspring, and which when forced inward causes the air pressure in the tube3 to be increased. The tube 3 leads directly, as shown in the drawings,(or indirectly through a heating apparatus) to a throttle valve 4 whichis operated by means of the lever 12, pivoted rod 11 and pivoted lever10. One end of the lever is connected by the rod 9 and crank 7 to avertical shaft at one end of the car, at the upper end of which shaft isa lever 8 shown in dotted lines, by which the operator can open or closethe throttle valve 4. The throttle valve may be operated from the otherend of the car by means of a similar lever 8connected by the crank 7 androd 9 to the opposite end of the pivoted lever 10. The compressed air isconducted by means of the tube 5 from the throttle valve 4 to the motor6 which drives the car. The motor 6 is provided with the usual reversingvalve gear, which is operated by the lever 16 in the usual manner tocause the car to movein eitherdirection. One end of the lever 16 isconnected by the rod and crank 14 to a vertical staff, at the upper endof which is the lever 25 at one end of the car, and to asimilar staffprovided with a lever 25 at the other end of the car,by means of the rodl5and crank 14:, so that the valves connected to the lever 16 may beoperated from either end of the car. The other end of the lever 16vibrates between two stems 17 and 26, which respectively project fromcasings 18 and 27, andin such manner, that, when the lever 16 has beenmoved in one direction through a prescribed distance, it comes intocontact with one of these stems and its further motion can only occur byforcing the stem into its casing. Fig. 2 shows more clearly thearrangement of the casing 18 and stem 17. In this figure, 18 is thecasing in section; 17 shows the stem to be the enlarged end of a boltpassing through the casing and held in position by the nut 20 and checknut 21. \Vithin the casing 18 and encircling the reduced portion of thestem 17, is the spring 19, which permits the stem 17 to be forced inwardinto the casing 18, only through a compression of the sprin The distancewhich the stem 17 projects from the casing 18 maybe regulated by the nut20 and check nut 21 and the projection of the stem 26 from the casing 27may be regulated in a similar manner, so that, within certain limits,the free movement of the lever 16, between the stems 17 and 26, may beregulated. The lever 10 is permitted to move in a direction to open thethrottle valve 4, through a certain prescribed distance, when the lever10 comes in contact with the stem 13 of the reducing valve 2. The lever10 can only be moved farther in such direction, by forcing the stem 13inward into the reducing valve 2, compressing the reducing valve springand increasing the pressureof the air delivercdinto the tube 3.

The operation of my invention is as follows. It being desired to movethe car in a direction to the right, in Fig. 1,the operator moves thelever 25, causing the lever 16 to turn until the end comes in contactwith the stem 17 and, in order to permit the entrance of a sufficientvolume of air, into the working cylinder of the motor 6, to start thecar, he continues the movement of the lever and, consequently, of thelever 16, forcing the stem 17 inward into the casing 18 against theresistance of the spring 19. At the same time, he moves the lever 8 and,through the intermediate connections, the levers l0 and 12, until thelever 10 comes in contact with the stem 13, thus opening the'throttlevalve 4 and permitting the compressed air to enter the working cylinderof the motor 6 through the tube 5. Should a greater air pressure herequired than is thus permitted to enter the motor, when the lever hasbeen stopped in its motion by the stem 13, the operator uses suflicientforce to move the lever 8 still farther, forcing inward the stem 13 inthe reducing valve and' permitting a higher air pressure to enter themotor 6. The car having been started in its motion, he relaxes histension upon the lever 8, permitting the stem 13 to be forced outward,by the spring in the reducing valve, to its normal positiom by which thepressure of the air delivered to the motor is again reduced to that forwhich the reducing valve is normally adjusted. He also relaxes thetension upon thelever 25, permitting the stem 17 to be forced out-wardin its casing 18 by the spring 19, by which the lever 16 is returned toits normal position for moving the car in that direction and thuscausing a re-adjustment of the motion of the valve gear by which workingcylinder, at each stroke, is reduced to the normal amount for economicaloperation. When it is desired to move the car in the volume ofcompressed air entering the within the casing 27. In this manner, whilethe operator has within his control the means for utilizing aconsiderable volume of air at a sufficiently high pressure to quicklystart the car in motion, no inadvertence on his part will permit thecontinuance of such use of the compressed air when it is no longerneeded, as both the volume and pressure of the air are automaticallyreduced to the point of normal requirement, as soon as he relaxes thephysical exertion necessary to increase either the volume or pressureused.

Fig. 3 shows myimprovementapplied to the ordinary reversing lever of alocomotive, in which the reversing lever 22 corresponds to the lever 16in Fig. 1. It is usually customary to use, in connection with the lever22 a notched quadrant 24, so that the lever 22 being moved in a desiredposition,'a latch 23 drops into a notch of the quadrant 24 and holds thevalve gear ina position corresponding to such position of the lever 22.The stems 17 and 26, in the casings 18 and 27 re spectively, correspondto those of similar numbers in Fig. 21 and are so located, withreference to the lever 22, that, when the lever 22 is moved to aposition where it comes in contact with either of the stems 17 or 26,the volume of steam or air entering the working cylinder is such asshould be normally required. The leveri22 may be locked in this positionby putting the latch 23 in the last notch, but it cannot be moved to aposition to increase the volume of steam or air used in the workingcylinder, without meeting the resistance of thespring behind the stem 17or 26, which resistance will immediately force the lever 22 back to thenormal position, as soon as the physical force of the operator isrelaxed.

For the purpose of thus permitting a free movement of the valve motion,effecting the entrance of different volumes of the steam or air to theworking cylinder, up to a certain point, and a further movement of thevalve gear against an elastic resistance, by which a greater volume ofair may be admitted to the working cylinder, it is evident that theresisting spring or medium may be placed at any other convenient pointin the train of mechanism operating the valve gear, than that shown inthe drawings. The same is also true of the position of the elasticspring, which ordinarily prevents the use of a higher degree of pressurethan one specifically determined. I do not, therefore, confine myself tothe specific positions of such springs, shown in the drawings, butmayplace them elsewhere in the operating mechanism as convenience maysuggest.

While I have also shown a spring as the medium of resistance, in eachcase described, it is obvious that any other elastic resistance, such asthe pressure of a gas or liquid against a piston, would produce the sameeffect,as will be readily understood, and I do not confine myself to theuse of any specific form of elastic resistance. It is also obvious thatby simple mechanical connection of the various levers the separatevalves for regulating the pressure and volume may both be operated byone lever on each platform.

While I have illustrated my improvement as applied to separate valvesfor controlling the pressure and volume, it is apparent that there is nonecessary connection between them, and that the invention resides in theuse of an elastic resistance to control the movement of a valve beyond acertain predetermined point, whatever may be the purpose for which thevalve is used.

What I claim as my invention is- V In a fluid pressure engine, thecombination of a valve operating mechanism, having a predeterminedlimited range of free movement, with an elastic resistance deviceopposing any movement of such operating mechanism beyond suchpredetermined range.

In testimony whereof I have hereunto affixed my signaturethis 3d day ofAugust, 1893.

ROBERT A. PARKE.

Witnesses:

THOMAS B. KERR, ROBERT SHERIDAN.

